Conductive pads defined by embedded traces

ABSTRACT

An assembly and method of making same are provided. The assembly can include a first component including a dielectric region having an exposed surface, a conductive pad at the surface defined by a conductive element having at least a portion extending in an oscillating or spiral path along the surface, and a an electrically conductive bonding material joined to the conductive pad and bridging an exposed portion of the dielectric surface between adjacent segments. The conductive pad can permit electrical interconnection of the first component with a second component having a terminal joined to the pad through the electrically conductive bonding material. The path of the conductive element may or may not overlap or cross itself.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from Korean Application No.10-2010-0113272 filed Nov. 15, 2010, the disclosure of which is herebyincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to formation of microelectronic devices,especially the formation of conductive pads.

Microelectronic devices generally comprise a thin slab of asemiconductor material, such as silicon or gallium arsenide, commonlycalled a die or a semiconductor chip. Semiconductor chips are commonlyprovided as individual, prepackaged units. In some unit designs, thesemiconductor chip is mounted to a substrate or chip carrier, which isin turn mounted on a circuit panel, such as a printed circuit board.

The active circuitry is fabricated in a first face of the semiconductorchip (e.g., a front surface). To facilitate electrical connection to theactive circuitry, the chip is provided with bond pads on the same face.The bond pads are generally made of a conductive metal, such as copper,or aluminum, around 0.5 μm thick. The bond pads could include a singlelayer or multiple layers of metal. The size of the bond pads will varywith the device type but will typically measure tens to hundreds ofmicrons on a side.

Microelectronic devices are typically mounted in packages which includea dielectric element having a set of conductive elements thereon, suchas terminals or other conductive pads. A packaged chip or in some casesa bare chip can be mounted to and electrically interconnected with theconductive pads of a circuit panel. Traditionally, the conductive padson such dielectric element or circuit panel can be formed by rasteringor photolithography. These processes can involve drawbacks. Laserformation of conductive pads by rastering can create pads with unevensurfaces, as each successive rastered segment partially overlaps theprevious segment. Photolithography can be inefficient, particularly forsmall production quantities, pads, as it can be burdensome to design,test and correct a mask that is optimized for a particular applicationor system.

Size is a significant consideration in any physical arrangement ofchips. The demand for more compact physical arrangements of chips hasbecome even more intense with the rapid progress of portable electronicdevices. Merely by way of example, devices commonly referred to as“smart phones” integrate the functions of a cellular telephone withpowerful data processors, memory and ancillary devices such as globalpositioning system receivers, electronic cameras, and local area networkconnections along with high-resolution displays and associated imageprocessing chips. Such devices can provide capabilities such as fullinternet connectivity, entertainment including full-resolution video,navigation, electronic banking and more, all in a pocket-size device.Complex portable devices require packing numerous chips into a smallspace. Moreover, some of the chips have many input and outputconnections, commonly referred to as “I/O's.” These I/O's must beinterconnected with the I/O's of other chips. The interconnectionsshould be short and should have low impedance to minimize signalpropagation delays. The components which form the interconnectionsshould not greatly increase the size of the assembly. Similar needsarise in other applications as, for example, in data servers such asthose used in internet search engines. For example, structures whichprovide numerous short, low-impedance interconnects between complexchips can increase the bandwidth of the search engine and reduce itspower consumption.

Despite the advances that have been made or proposed in the fabricationof components with conductive pads further improvements can still bemade.

BRIEF SUMMARY OF TEE INVENTION

A first aspect of the present invention is an assembly including a firstcomponent including a dielectric region having an exposed surface; aconductive pad at the surface permitting electrical interconnection ofthe first component with a second component, the conductive pad definedby a conductive element having at least a portion extending in at leastone of an oscillating or spiral path along the surface such that atheoretical straight line intersects at least three segments of thepath, and at least two adjacent segments of the conductive element areseparated by a portion of the surface not covered by the conductiveelement, the conductive element extending from the surface to a topsurface at a height above the surface and having a length along thesurface that is at least ten times the height; and an electricallyconductive bonding material having a melting temperature below 300° C.joined to the conductive pad and bridging the exposed portion of thesurface between the at least two adjacent segments, wherein theconductive element has edge surfaces extending away from the top surfaceand the electrically conductive bonding material contacts the top andedge surfaces of the conductive element.

In accordance with certain embodiments of this first aspect, theassembly may further include the second component having a terminaljoined to the conductive pad through the electrically conductive bondingmaterial. The path of the conductive element may not overlap or crossitself. The path of the conductive element may at least overlap or crossitself. The conductive element may occupy less than seventy-five percentof an area of the surface of the dielectric region within a circularboundary defined by outermost edges of the pad. The first component mayfurther include a substrate having a substrate surface, the dielectricregion at least partly overlying the substrate surface. The substratesurface may be a top surface of the substrate, the substrate furtherhaving a bottom surface remote from the top surface, an openingextending between the top and bottom surfaces, and a second conductiveelement disposed at the bottom surface, the pad being electricallyconnected to the second conductive element through the opening in thesubstrate and an opening in the dielectric region.

The surface of the dielectric region may be exposed at the exposedsurface of the first component, the first component further having abottom surface remote from the exposed surface, an opening extendingbetween the top and bottom surfaces, and a second conductive elementdisposed at the bottom surface, the pad being electrically connected tothe second conductive element through the opening in the first componentand an opening in the dielectric region. The exposed surface may be arear face, and the first component may have a front face remote from therear face and an opening extending between front and rear faces, andwherein the conductive element is exposed at the rear face and at leasta portion of the conductive element extends along an interior surface ofthe opening. The first component may have at least one contact at thefront face, wherein electrical connection between the at least onecontact and the conductive element may be made through the opening. Thefirst component may be a microelectronic element having a plurality ofactive semiconductor devices adjacent the front face.

The first component may be a microelectronic element having a pluralityof contacts at the surface, and the assembly may further include a traceelectrically connecting the conductive pad with at least one of theplurality of contacts. The first component may be a dielectric elementhaving a plurality of traces thereon, wherein the conductive pad iselectrically connected with at least one of the traces. The surface maybe a first surface, the first component may be a microelectronic elementhaving a plurality of contacts at a second surface remote from the firstsurface, and the conductive pad may be electrically connected with atleast one of the plurality of contacts. The electrically conductivebonding material may be solder. The pad may include a surface layerincluding at least one of nickel or gold, and the electricallyconductive bonding material contacts the surface layer. A system mayinclude an assembly as described above and one or more other electroniccomponents electrically connected to the assembly. The system mayfurther include a housing, the assembly and the other electroniccomponents being mounted to the housing.

A second aspect of the present invention is an assembly including afirst component including a dielectric region having an exposed surface;a continuous groove extending along the surface and having at least aportion extending in a curved path along the surface, the groove havinga floor disposed below the surface; a conductive pad exposed at thesurface permitting electrical interconnection of the first componentwith a second component, the conductive pad defined by a conductiveelement having cross-sectional dimensions at least partly defined by thegroove, extending from the floor of the groove to a height above thefloor, and having at least a portion extending in at least one of anoscillating or spiral path along the surface such that a theoreticalstraight line intersects at least three segments of the path, theconductive element having at least two adjacent segments separated by anexposed portion of the surface of the dielectric region, and theconductive element having a length along the surface that is at leastten times greater than the height; and a an electrically conductivebonding material having a melting temperature below 300° C. joined tothe conductive pad and bridging the exposed portion of the surfacebetween the at least two adjacent segments.

In accordance with certain embodiments of this second aspect, the firstcomponent may be a microelectronic element having a plurality ofcontacts at the surface thereof and a plurality of active semiconductordevices adjacent the surface, and the assembly may further include atrace electrically connecting the conductive pad with at least one ofthe plurality of contacts. The first component may be a dielectricelement having a plurality of traces thereon, wherein the conductive padmay be electrically connected with at least one of the traces. Thesurface may be a first surface, the first component may be amicroelectronic element having a plurality of contacts at a secondsurface remote from the first surface, and a plurality of activesemiconductor devices adjacent the second surface, and the conductivepad may be electrically connected with at least one of the plurality ofcontacts.

The assembly may further include the second component, the electricallyconductive bonding material joining the conductive pad with a terminalof the second component. The electrically conductive bonding materialmay be solder. The first component may include an opening extendingbetween the front and rear faces and at least a portion of theconductive element extending along an interior surface of the opening,at least a portion of the groove extending along the interior surface,the conductive element extending within the portion of the groove.Electrical connection between the at least one contact and theconductive element may be made through the opening. The height of theconductive element may be greater than a distance between the floor andthe surface of the dielectric region. The height of the conductiveelement may be equal to or less than a distance between the floor andthe surface of the dielectric region.

Outermost edges of the pad may define a circular or square-shapedboundary with respect to the surface. The path of the conductive elementmay not overlap or cross itself. The path of the conductive element mayat least overlap or cross itself. The conductive element may occupy lessthan seventy-five percent of the surface area of the surface within theboundary. The height of the conductive element may be greater than adistance between the floor and the surface such that the conductiveelement has top surface exposed at the surface of the dielectric regionand edge surfaces extending away from the top surface, the electricallyconductive bonding material contacting the top and edge surfaces of theconductive element. The pad may include a surface layer including atleast one of nickel or gold.

The surface of the dielectric region may be exposed at the exposedsurface of the first component, the first component may further includea bottom surface opposed from the exposed surface, an opening extendingbetween the exposed and bottom surfaces, and a second conductive elementoverlying the bottom surface, the pad being electrically connected tothe second conductive element through the opening in the first componentand an opening in the dielectric region. The dielectric region mayinclude a solder mask. The dielectric region may be a polymericmaterial. The dielectric region may be an inorganic material. Thedielectric region may include two or more stacked layers of dielectricmaterials, at least two adjacent layers thereof including differentmaterials. A system may include an assembly as described above and oneor more other electronic components electrically connected to theassembly. The system may further include a housing, the assembly and theother electronic components being mounted to the housing.

A third aspect of the present invention is a method of forming aconductive structure on a first component, including (a) forming acontinuous groove extending along an exposed surface of a dielectricregion of a first component by removing a portion of the dielectricregion, the groove having at least a portion extending in a curved path,the groove having a floor disposed below the surface; (b) forming aconductive pad exposed at the surface permitting electricalinterconnection of the first component with a second component, theconductive pad defined by a conductive element having cross-sectionaldimensions and a path at least partly defined by the path of the grooveand extending from the floor of the groove to a height above the floor,the conductive element having at least a portion extending in at leastone of an oscillating or spiral path along the surface such that atheoretical straight line intersects at least three segments of thepath, the conductive element having at least two adjacent segmentsseparated by a portion of the surface, the conductive element having alength along the surface that is at least ten times greater than theheight, the conductive element at least partially embedded in thegroove; and (c) performing one of: applying an electrically conductivebonding material having a melting temperature below 300° C. to theconductive pad, the electrically conductive bonding material bridgingthe exposed portion of the surface between the at least two adjacentsegments; or assembling the component with the second component with anelectrically conductive bonding material having a melting temperaturebelow 300° C. joining the conductive pad to a conductive pad of thesecond component, the electrically conductive bonding material bridgingthe exposed portion of the surface of the dielectric region between theat least two adjacent segments.

In accordance with certain embodiments of this third aspect, the heightof the conductive element may be greater than a distance between thefloor and the surface. The conductive element may include an exposed topsurface parallel to the surface of the dielectric region and exposedvertical surfaces extending between the top surface thereof and thesurface of the dielectric region, the electrically conductive bondingmaterial being in contact with the top and vertical surfaces of theconductive element. The height of the conductive element may be equal toor less than a distance between the floor and the surface. A distancebetween the floor and the surface may be greater than a width of theconductive element.

Step (b) may include forming the conductive element such that it doesnot overlap or cross itself. Step (b) may include forming the conductiveelement such that it at least overlaps or crosses itself. Step (c) mayinclude forming a catalyst layer overlying at least the floor of thegroove, and then selectively depositing a metal onto an area where thecatalyst layer may be present to form the conductive element. Theelectrically conductive bonding material may extend at least betweenoutermost edges of the pad of the first component. Step (b) may includeplating a surface layer including at least one of nickel or gold exposedat a surface of the pad of the first component.

The first component may include a second region, the dielectric regionoverlying the second region when step (a) and step (b) are performed.The substrate may have a bottom surface opposed from the top surface, anopening extending between the top and bottom surfaces, and an conductiveelement overlying the lower surface, the pad of the first componentbeing electrically connected to the conductive element through theopening in the substrate and an adjacent opening in the dielectricregion.

Step (a) may be performed by processing including at least one of:directing a laser toward at least the surface to ablate the portion ofthe dielectric region, mechanical milling, or sandblasting. Step (b) mayinclude positioning a metal stencil to overlie the dielectric region,the metal stencil having at least one opening, and removing the portionof the dielectric region exposed through the at least one opening bysandblasting. Step (b) may include removing a portion of the dielectricregion by mechanical milling. Step (b) may include depositing aconductive material overlying the surface of the dielectric region andat least a portion of the groove, and removing the conductive materialoverlying at least a portion of the surface to expose the surface of thedielectric region.

Step (c) may include applying the electrically conductive bondingmaterial to the conductive pad, the electrically conductive bondingmaterial bridging the exposed portion of the surface between the atleast two adjacent segments. Step (c) may include assembling thecomponent with the second component with the electrically conductivebonding material joining the conductive pad to the conductive pad of thesecond component, the electrically conductive bonding material bridgingthe exposed portion of the surface of the dielectric region between theat least two adjacent segments.

A fourth aspect of the present invention is a method of forming a firstcomponent assembly, the method including (a) plating a conductive padonto a planar surface of a mandrel, the conductive pad defined by aconductive element extending along the surface and having at least aportion extending in a curved path along the surface; (b) at leastpartially embedding the conductive pad into a dielectric material; (c)removing the mandrel to form the first component having a dielectricregion and the conductive pad exposed at a surface of the dielectricregion for permitting electrical interconnection of the component with asecond component, the conductive element of the conductive pad having atleast a portion extending in at least one of an oscillating or spiralpath along the surface of the dielectric region such that a theoreticalstraight line intersects at least three segments of the path, theconductive element having at least two adjacent segments thereofseparated by a portion of the surface of the dielectric region, at leasta portion of the surface of the dielectric region being exposed betweenthe at least two segments, the conductive element having a length alongthe surface of the dielectric region that is at least ten times greaterthan the height; and (d) performing one of: applying an electricallyconductive bonding material having a melting temperature below 300° C.to the conductive pad, the electrically conductive bonding materialbridging the exposed portion of the surface between the at least twoadjacent segments; or assembling the component with the second componentwith an electrically conductive bonding material having a meltingtemperature below 300° C. joining the conductive pad to a conductive padof the second component, the electrically conductive bonding materialbridging the exposed portion of the surface of the dielectric regionbetween the at least two adjacent segments.

In accordance with certain embodiments of this fourth aspect, themandrel may include a metal sheet, and step (c) may include etching themetal sheet to expose the pad of the first component. Step (b) mayinclude embedding the conductive pad of the first component into an atleast partially cured dielectric region which includes the dielectricmaterial. Step (b) may include depositing the dielectric material tocontact at least a portion of the conductive pad of the first component.Step (d) may include applying the electrically conductive bondingmaterial to the conductive pad, the electrically conductive bondingmaterial bridging the exposed portion of the surface between the atleast two adjacent segments. Step (d) may include assembling thecomponent with the second component with the electrically conductivebonding material joining the conductive pad to a conductive pad of thesecond component, the electrically conductive bonding material bridgingthe exposed portion of the surface of the dielectric region between theat least two adjacent segments.

A fifth aspect of the present invention is a method of forming acomponent assembly, the method including (a) providing a lead framehaving a conductive pad, the conductive pad defined by a conductiveelement extending along the surface and having at least a portionextending in a curved path along the surface; (b) at least partiallyembedding the lead frame in a dielectric material, wherein theconductive pad may be exposed at a surface of the dielectric materialfor permitting electrical interconnection of the component with a secondcomponent, the conductive element of the conductive pad having at leasta portion extending in at least one of an oscillating or spiral pathalong the surface of the dielectric region such that a theoreticalstraight line intersects at least three segments of the path, theconductive element having at least two adjacent segments thereofseparated by a portion of the surface of the dielectric region, at leasta portion of the surface of the dielectric region being exposed betweenthe at least two segments, the conductive element having a length alongthe surface of the dielectric region that may be at least ten timesgreater than the height; and (c) performing one of: applying anelectrically conductive bonding material having a melting temperaturebelow 300° C. to the conductive pad, the electrically conductive bondingmaterial bridging the exposed portion of the surface between the atleast two adjacent segments; or assembling the component with the secondcomponent with an electrically conductive bonding material having amelting temperature below 300° C. joining the conductive pad to aconductive pad of the second component, the an electrically conductivebonding material bridging the exposed portion of the surface of thedielectric region between the at least two adjacent segments.

In accordance with certain embodiments of this fifth aspect, step (c)may include applying the conductive bonding material to the conductivepad, the conductive bonding material bridging the exposed portion of thesurface between the at least two adjacent segments. Step (c) may includeassembling the component with the second component with the electricallyconductive bonding material joining the conductive pad to a conductivepad of the second component, the electrically conductive bondingmaterial bridging the exposed portion of the surface of the dielectricregion between the at least two adjacent segments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a substrate having a groove in accordancewith the present invention.

FIG. 2 is a side sectional view of the substrate of FIG. 1 taken alongthe line A-A.

FIG. 3 is a top plan view of the substrate of FIG. 1 having a pad.

FIG. 4 is a side sectional view of the substrate of FIG. 3 taken alongthe line B-B.

FIGS. 5-7 are side sectional views of alternative embodiments of thesubstrate and pad of FIG. 3.

FIG. 8 is a top plan view of the substrate and pad of FIG. 3 with abonding material.

FIG. 9 is a side sectional view of the substrate and bonding material ofFIG. 8 taken along the line C-C.

FIG. 10 is a side sectional view of the substrate, pad, and bondingmaterial of FIG. 8 attached to a second component.

FIG. 11 is a top plan view of an alternative embodiment of a substratehaving a pad.

FIG. 12 is a top plan view of the pad of FIG. 3 shown positioned withina boundary.

FIGS. 13 and 14 are top plan views of alternative embodiments of asubstrate having a pad in accordance with the present invention.

FIG. 15 is a top perspective view of a substrate having a padelectrically connected with a chip in accordance with the presentinvention.

FIG. 16 is a side sectional view of the substrate of FIG. 15 taken alongthe line E-E.

FIG. 17 is a side sectional view of an alternative embodiment of thesubstrate and pad of FIG. 15.

FIG. 18 is a side sectional view of the substrate and pad of FIG. 17with a bonding material.

FIG. 19 is a top perspective view of a mandrel having a pad formedthereon in accordance with the present invention.

FIG. 20 is a side sectional view of the mandrel and pad of FIG. 15 takenalong the line F-F.

FIGS. 21 and 22 are side sectional views showing the pad of FIG. 19being embedded into a dielectric region.

FIG. 23 is a schematic depiction of a system according to one embodimentof the invention.

DETAILED DESCRIPTION

As used in this disclosure, a statement that an electrically conductiveelement is “exposed at” a surface of a dielectric element indicates thatthe electrically conductive element is available for contact with atheoretical point moving in a direction perpendicular to the surface ofthe dielectric element toward the surface of the dielectric element fromoutside the dielectric element. Thus, a terminal or other conductiveelement which is exposed at a surface of a dielectric element mayproject from such surface; may be flush with such surface; or may berecessed relative to such surface and exposed through a hole ordepression in the dielectric.

A first embodiment of an assembly 100, shown in FIGS. 8 and 9, will bedescribed according to its method of construction. Assembly 100 includesa first component 105 as shown, for example, in FIGS. 1 and 2. Thecomponent includes at least a dielectric region 120 and may also includea supporting element, e.g., a substrate, underlying the dielectricregion 120. The first component may be, for example, a dielectricelement to be fabricated into a chip carrier, other component of apackage, or a circuit panel. Substrate 110 can be an additionaldielectric layer of the component 105 or can be other structure, asdescribed further below. As seen in FIGS. 1-2. A continuous groove 124having a floor 126 is formed extending along the surface 122 of thedielectric region. Floor 126 is defined as the lowest portion of groove124. At least a portion of groove 124 extends in a curved path withrespect to surface 122.

Groove 124 can be formed by removing a portion of dielectric region 120,which in one example can be done by laser ablation by directing a laserat surface 122. For example, a system, e.g., a computer, can be used tomove an illumination spot produced by the laser to different locationsof surface 122. The laser ablates or otherwise removes a portion of asacrificial layer (if present) and a portion of dielectric region 120.Groove 124 is depicted with floor 126 being curved or rounded, thoughother cross-sections, such as rectangular, may be formed eitherpurposefully or as a result of the constraints of using a laser.

Though not depicted, the sacrificial layer may be provided overlyingsurface 122 of dielectric region 120 prior to the step of ablating withthe laser. The sacrificial layer typically can be a polymeric materialand has an exposed surface that conforms to a contour of surface 122.The sacrificial layer can be applied by spray-coating, spin-coating,dipping, or other method. In a particular embodiment, the sacrificiallayer is removable by chemical means, such as by using an etchant. Inone embodiment, the sacrificial layer is removable by peeling. While asacrificial layer can be used, formation of groove 124 does not requirethe use of a sacrificial layer.

After forming the groove, a conductive element is formed which extendsin a direction of the groove along surface 122. In one embodiment,catalyst layer can be formed overlying the exposed portions ofdielectric region 120 and/or the sacrificial layer, if present. Thecatalyst layer overlies at least floor 126 of groove 124 and istypically comprised of a thin layer of metal particles which cancatalyze a subsequent metal deposition process, for example, asubsequent aqueous deposition process used in plating metal layersthereon. In one example, the catalyst layer can include platinumparticles. In one example, the catalyst layer can be formed by providinga liquid containing the catalyst particles to the exposed surfaces ofthe sacrificial layer, for example, by dipping the substrate in a bathcontaining the catalyst particles. The catalyst layer typicallyuniformly coats first component 105. The sacrificial layer, if present,is removed from first component 105, thereby also removing the catalystlayer disposed on the sacrificial layer. In this way, after thesacrificial layer has been removed the catalyst layer is disposed onlyin groove 124. If no sacrificial layer is present, the catalyst layercan be deposited only in or along areas of first component 105 that areto be plated to form a conductive element, which, for example, can beonly the area in groove 124.

A seed layer can then be selectively deposited onto the catalyst layer,and the process can continue with the deposition of one or more metallayers, which can include any of or all of an adhesion layer, a barriermetal layer, and a primary metal layer. Typically, such seed layer,adhesion layer, barrier metal layer or primary metal layer is depositedby plating. The result of this process of selectively depositing a metalonto an area where the catalyst layer is present is the formation of aconductive element 132, as seen in FIGS. 3 and 4, formed in groove 124.Shown more clearly in FIG. 4, cross-sectional dimensions of conductiveelement 134, i.e., a width and a height or thickness of conductiveelement 132 above floor 126 of groove 124, are at least partly definedby the groove 124. Conductive element 132 is depicted as having a planartop surface 135, although in practice, some degree of a “U” shapedsurface may occur. The height of conductive element 132 may thusly bedefined as extending from its lowest point (i.e., the lowest point ofgroove 124) to its highest point. Corresponding cross-sectionaldimensions of a depth 128 and a width 130 of groove 124, shown in FIG.2, aid in defining conductive element 132. Depth 128 is measured betweenfloor 126 and surface 122 of dielectric region 120. The depth can begreater than the width 130 of the groove, as measured in a perpendiculardirection along surface 130, being perpendicular to the depth 128 and alengthwise direction 125 of the groove 124. Further, depth 128 may begreater than a width of conductive element 132, which corresponds towidth 130. In this way, conductive element 132 can have a contour whichconforms to the inner surface of groove 124 and is at least partiallyembedded within groove 124 in dielectric region 120. In one embodiment,the height of conductive element 132 can be at least substantially thesame throughout the path of the conductive element along the segmentsthereof.

In a variation of the above-described embodiment, the sacrificial layercan be removed after one or more or the metal layers is deposited whichmake up conductive element 132. For example, in one embodiment, thesacrificial layer can be removed after depositing any or all of a seedlayer, an adhesion layer, a barrier metal layer or other metal layerprovided before the primary metal layer is deposited. In such case, thesacrificial layer may be removed in a “lift-off” process from thedielectric region, such as by etching, peeling or other method. Then,after removing the sacrificial layer, the metal deposition can continuewith the deposition of one or more subsequent metal layers including theprimary metal layer to form conductive element 132.

As seen in FIGS. 3-4, Conductive element 132 forms a pad 134 exposed atsurface 122 of dielectric region 120. Pad 134 can be connected to or beformed integrally with one or more other conductive elements (not shown)such as a conductive trace, other conductive pad, or other circuitcomponent. Such other conductive element can extend from or be connectedto one or more locations of conductive element 134, such as end 139 orpath location 141.

Pad 134 permits electrical interconnection of first component 105 with asecond component 107, shown in FIG. 10. Pad 134 is defined by conductiveelement 132, which has cross-sectional dimensions and a path at leastpartly defined by the path of groove 124. Conductive element 132 extendsfrom floor 126 of groove 124 to a height above floor 126. As shown inFIG. 4, the height of conductive element 132 is greater than a distancebetween floor 126 and surface 122. However, in alternative embodimentsof the present invention shown in FIGS. 5 and 6, the height of theconductive element above the floor can be equal to or less than suchdistance, respectively. In FIG. 5, a conductive element 232 extends to aheight above a floor 226 equal to the distance between floor 226 and asurface 222 of a dielectric region 220. In this case, top surface 244 ofconductive element 232 can be co-planar with surface 222 of thedielectric region. FIG. 6 shows a conductive element 332 extending to aheight above a floor 326 less than the distance between floor 326 and asurface 322 of a dielectric region 320. Such that a top surface 344 ofthe conductive element is disposed below the surface 322 of thedielectric region.

As shown in FIG. 3, conductive element 132 includes at least twoadjacent segments 136, 138 that are separated by a portion 137 ofdielectric region 120. Accordingly, it can be said that a theoreticalstraight line 199 intersects at least three segments 136, 138, and 150of conductive element 132. Conductive element 132 in its entirety has alength along surface 122 that is at least ten times greater than itsheight 133, e.g., as, measured from floor 126 to top surface 135. Pad134 can be constructed such that conductive element 132 occupies lessthan about seventy-five percent of an area of surface 122 of dielectricregion 120 within a generally circular-shaped boundary 146, shown inFIG. 12, defined in general by the outermost edges of pad 134. In apreferred embodiment, a conductive element according to the presentinvention occupies ten to seventy-five percent of an area within suchboundary, and in certain embodiments, a conductive element can occupyabout twenty-five percent of an area within such boundary.

First component 105 is shown and described in one configuration,although other configurations of assembly 100 and first component 105may be realized by the present invention and will be described morethoroughly below. For example, first component 105 includes conductiveelement 132 that has a spiral path (as shown in FIGS. 1 and 3). In otherexamples, a first component 505 can include a conductive element 532having a sinusoidal path on a surface 522 (as shown in FIG. 13), or afirst component 605 can include a conductive element 632 having anoscillating path on a surface 622 (as shown in FIG. 14). A sinusoidalpath is generally wave-shaped, and an oscillating path is one thatgenerally extends in a side-to-side manner along the direction from thebeginning to the end of the conductive element. An “oscillating path”broadly describes an array of configurations of a conductive element,including a sinusoidal path. Moreover, an oscillating path need not beuniform as shown in FIG. 14. Conductive element 632 may form anoscillating path that forms a portion of a pad, with one or moreportions being configured in other manners. For example, a pad mayinclude a portion that forms an oscillating path and another portionthat crosses the oscillating path but cannot be characterized by anyparticular type of shape. An oscillating path can, for instance, be atriangular wave shape, a zig-zag pattern, or any other similar pattern.It is not necessary that the oscillating path have segments 636 ofuniform length or that the path reverse direction with the same angle634 between segments. At least some adjacent segments of the path maynot be joined together at both ends thereof. Rather, in some cases, theconductive element can have an oscillating path which “meanders” withina defined area set for a conductive pad, in which segments of the pathcan be of varying length and can have varying angles between segments.In the case of conductive elements 532 and 632, each may occupy lessthan about seventy-five percent of an area of their respective surface522, 622 within a generally square-shaped boundary defined in general bythe outermost edges of conductive elements 532 and 632, respectively. Inaccordance with the present invention, any other desired shape orconfiguration of a conductive element may be realized to form a pad. Oneadvantage of the present invention is the ability to define a generalouter boundary of a pad with any pattern of a conductive elementdisposed within said boundary. Thus, the conductive element does notrequire a precise pattern, but is effective due to its overall structureas a pad. Conductive element 132, as shown in FIG. 3, does not overlapor cross itself along its path. In alternative embodiments, such as thatdepicted in FIG. 11, a conductive element 432 of a first component 405may overlap or cross itself in one or more areas on a surface 422.

In another method of forming pad 134, a conductive material can bedeposited overlying surface 122 of dielectric region 120 and at least aportion of groove 124. Certain of the conductive material overlying atleast a portion of surface 122 can then be removed to expose surface 122of dielectric region 120.

After pad 134 is formed, an electrically conductive bonding material 140can be deposited at least partly overlying pad 134, as shown in FIGS. 8and 9. The electrically conductive bonding material 140, whichpreferably has a melting temperature below 300° C. and may be a soldermaterial, can extend at least between outermost edges of pad 134 so asto entirely cover pad 134 when viewed from a direction normal to surface122, as shown in FIG. 8. The electrically conductive bonding material140 is joined to conductive pad 134 to bridge portion 137 of dielectricregion 120 between segments 136, 138 of conductive element 132, shownmore clearly in FIG. 3. Second component 107, shown in FIG. 10, includesa terminal 108 joined to pad 134 through bonding material 140. Whilebonding material 140 can be applied directly to pad 132 prior toassembling first component 105 with second component 107, bondingmaterial 140 can alternately be applied only to the terminal 108 of thesecond component 107 or can be applied separately to each of the pad 132and the terminal 108 before assembling the components together.

As shown in FIG. 9 where conductive element 132 extends to a heightabove surface 122, conductive element 132 includes an exposed topsurface 144 exposed above surface 122 of dielectric region 120 andexposed “vertical surfaces” 142 extending between top surface 144 andsurface 122. “Vertical surfaces” 142 are edge surfaces that extend awayfrom top surface 144, although they may or may not be in a vertical ornormal direction with respect to the top surface 144 and dielectricregion surface 122. Bonding material 140 is in contact with top surface144 and vertical surfaces 142. In alternate embodiments, such as thosedepicted in FIGS. 5 and 6, the bonding material contacts the conductiveelement and surface in a different manner. In FIG. 5, a top surface 244is essentially flush with surface 222 of dielectric region 220. Thus,the bonding material would have an essentially planar contact surfacewith the top surfaces 244 of conductive element 232 and surface 222. InFIG. 6, with a top surface 344 of conductive element 332 disposed belowsurface 322, the bonding material also contacts vertical surfaces 348 ofgroove 324 exposed between top surface 344 of conductive element 332 andsurface 322 of dielectric region 320. It will be appreciated that themore surface area with which the bonding material can be contacted, thegreater adhesion between the bonding material and the first component.Furthermore, a surface layer including nickel, gold, or another metalcan be plated or otherwise exposed at one or more surface of pad 134,such as at the top and edge surfaces 142, 144.

In accordance with the present invention, embodiments of the firstcomponent can be comprised of a single dielectric region, can include asubstrate underlying a dielectric region, or can comprise more than onedielectric regions or layers in a stacked formation. The dielectricregion can comprise two or more stacked layers of dielectric materials,with at least two adjacent layers thereof including different materials.The dielectric region typically includes one or more dielectricmaterials such as silicon dioxide in any form, other dielectric compoundof silicon, a polymeric material, or other inorganic dielectricmaterial, such as a ceramic material, among others. A substrateaccording to the present invention typically consists essentially of amonocrystalline semiconductor material such as, for example, silicon, analloy of silicon with another material, one or more III-V semiconductorcompounds such as gallium arsenide among others, or one or more II-VIsemiconductor compounds. In a particular embodiment, the substrate canbe a silicon-on-insulator substrate which includes a buried oxide(“BOX”) layer that separates an active semiconductor device layer at afront face from a bulk semiconductor region at a rear face.

In an embodiment shown in FIG. 7, substrate 110 includes an opening 116extending between the rear face 112 and front face 114, and a pluralityof conductive elements 118 disposed at front face 114. Conductiveelement 132 electrically connects pad 134 to at least one of conductiveelements 118 by extending through opening 116 in substrate 110 and anadjacent opening in dielectric region 120. At least a portion of groove124 can extend along an interior surface of opening 116, and conductiveelement 132 can extend within the portion of groove 124.

Another embodiment of a first component 705 is shown in FIGS. 15-18, andincludes a chip 710 and a passivation layer 703 overlying an uppersurface of chip 710. A bond pad 750 is disposed on an exposed surface704 of passivation layer 703, which is a dielectric region having anexposed surface. A conductive pad 734 is also formed on surface 704 in amanner as described above. A trace 752 is electrically connected withchip 750 and extends along surface 704 to electrically connect with aportion of pad 734. Trace 752 may be formed in conjunction with pad 734during a process as outlined above, or may be formed to electricallyconnect chip 750 with pad 734 after pad 734 has been formed. A pluralityof traces can also or alternatively be positioned in the position wheretrace 752 is disposed, as shown in FIG. 15.

Pad 734 allows for electrical connection between chip 750 and anexternal component that can be joined thereto as described above withreference to FIG. 10, for example. In that regard, as shown in FIG. 17,a solder mask 756 may be deposited overlying passivation layer 703 andtrace 752, such as by using a photolithographic method. Pad 132 isthusly left exposed and may be covered by an electrically conductivebonding material 740 (FIG. 18). Another component may then beelectrically connected to chip 750 through the bonding material 740 in amanner similar to that depicted in FIG. 10. Alternatively, a secondcomponent having a terminal with bonding material thereon can be joinedto pad 734 to form the electrical connection.

A further embodiment is depicted in FIGS. 19-22, which shows anothermethod of forming a first component 805 in accordance with the presentinvention. A conductive pad 834 (FIGS. 19-20) is formed on a planarsurface 862 of a mandrel 860 or other type of lead frame. Pad 834 isformed as a plated conductive element in a similar configuration asdiscussed above. Mandrel 860 is then positioned adjacent a dielectricregion 820 such that pad 834 is adjacent a surface 822 of dielectricregion 820 (FIG. 21). Force is applied to mandrel 860 to embed pad 834into dielectric region 820, which may be at least partially cured.Mandrel 860 is then removed, with the resulting first component 805(FIG. 22) being similar to those in the above-described embodiments.

In certain embodiments, mandrel 860 may be comprised of one or moremetal sheets, and the step of removing mandrel 860 is conducted byetching away each metal sheet to expose the pad 834. In otherembodiments, dielectric region 820 may not be pre-formed, but rather, adielectric material may be deposited onto surface 862 of mandrel 860,and then mandrel 860 removed to form first component 805.

In any or all of the embodiments described herein, a first componenthaving a spiral or oscillating path conductive pad as described above,or formed according to a technique described above, can be joined orelectrically connected to a second component with an electricallyconductive bonding material contacting surfaces of the conductive pad ina manner as described above, and contacting a terminal of the secondcomponent. The bonding material bridges the portion of the surface ofthe dielectric region between the at least two adjacent segments of theconductive pad. The bonding material can be applied to such conductivepad before assembling the first component with the second component, inwhich case the bonding material on the conductive pad will form part ofthe joint or electrically conductive connection between the first andsecond components. Alternatively, before assembling the first and secondcomponents the bonding material can be applied to a terminal of thesecond component and not applied to such conductive pad. During theassembling step, the bonding material from the terminal of the secondcomponent will flow onto surfaces of the conductive pad and will thenbridge the portion of the surface of the dielectric region between theat least two adjacent segments. In one example, an electricallyconductive joint can be formed by heating a bond metal such as solder toa temperature sufficient to cause the bond metal to flow, the bond metalthen contacting surfaces of such pad and a terminal of the secondcomponent juxtaposed therewith. The bond metal then re-solidifies againto form the electrically conductive joint. In another example, a bondingmaterial can be applied separately to such conductive pad and to aterminal of a second component, after which the first and secondcomponents can be brought together and joined as described above.

A first component according to the present invention can be amicroelectronic element having a plurality of active semiconductordevices adjacent the surface of the dielectric region. In alternateembodiments, the first component can be a microelectronic element havinga plurality of contacts at its surface, and can further include a traceelectrically connecting the conductive pad with at least one of theplurality of contacts. In still other embodiments, the first componentcan be a microelectronic element having a plurality of contacts atsurface, and the conductive pad can be electrically connected with atleast one of the plurality of contacts.

In certain embodiments of the present invention, a substrate consistsessentially of monocrystalline semiconductor material, and a dielectricregion overlying the substrate includes a layer of dielectric materialconforming to a contour of a sloped surface of the substrate. Inalternative embodiments, the substrate may consist essentially ofdielectric material, or may include a region consisting essentially ofconductive material with a dielectric region overlying the region ofconductive material.

The use of a laser to form conductive elements as an alternative tophotolithography may permit the layout of the elements to be changedmore easily. With the present method, changing the layout may onlyrequire a change to a computer program which controls the movement ofthe laser, since the laser's movement determines the shape anddimensions of the conductive element. This contrasts with the time andexpense required to create and verify a photomask used to form traces byphotolithography.

The embodiments described above can include grooves and apertures formedsuch as by a direct writing method, e.g., using a laser to define apath. However, other methods can be used to form such features accordingto the present invention. Mechanical milling can be utilized, wherein asmall diameter element, which can be referred to as a hammer, repeatedlystrikes the sacrificial layer, if present, and the dielectric region toloosen and remove such material to form a groove or aperture. Anothermethod that can be utilized is a sandblasting technique together with ametal stencil, which is positioned to overlie sacrificial layer and/ordielectric region and includes openings that are shaped in accordancewith a desired final pattern of the conductive elements. A sandblastingtechnique is employed by directing a sand-based material at thedielectric region in a direction such that the sand-based material willstrike the sacrificial layer and/or the dielectric region in the areasexposed through the openings. One or more grooves are thereby formed inthe dielectric region. These particular techniques of mechanical millingand sand-blasting can be considered “non-photolithographic techniques”because they do not rely primarily on patterning using exposure of aphotoresist through a photomask. Description of such patterningtechniques and other structures which can be formed therewith is foundin commonly owned U.S. application Ser. No. 12/842,669 filed Jul. 23,2010, the disclosure of which is incorporated by reference herein. Theremaining steps of the method of constructing a structure in accordancewith the present invention are as set forth above.

In one embodiment, the methods herein disclosed can achieve a topsurface of a pad having greater planarity than those formed by existingmethods, such as rastering. As the pads according to the presentinvention typically include segments separated by gaps, the planarity ofthe top surface can be achieved by top surfaces of adjacent segmentsbeing co-planar or substantially defining a single plane.

It is noted that certain methods of removing sacrificial layer requirethe sacrificial layer to be more brittle in nature. For instance, thesandblasting technique described above is more effectively carried outwith a more brittle sacrificial layer, so that the sand-based materialdoes not become embedded in the sacrificial layer rather than breakingand removing same.

In particular embodiments discussed above, the resulting assemblies canbe or include a microelectronic unit having active circuit elements,e.g., transistors, diodes, or other microelectronic ormicroelectromechanical devices therein, among others, and can havetraces which are formed by one or more of the techniques, e.g., evennon-photolithographic techniques, as described above. Also in certainembodiments discussed above, the resulting assemblies can be or includean interposer structure having a substrate of at least one ofsemiconductor or dielectric material which has traces formed asdescribed above but which does not have active circuit elements therein.An interposer structure or component in accordance such embodiments canhave conductive elements exposed at one or more of the front and rearfaces for interconnection with one or more external components such as,for example, a microelectronic element, substrate or circuit panel.

In particular embodiments discussed above, the resulting assemblies canbe or include a microelectronic unit having active circuit elements,e.g., transistors, diodes, or other microelectronic ormicroelectromechanical devices therein, among others, and have tracesformed by one or more of the methods described above. Also in certainembodiments discussed above, the resulting assemblies can be or includean interposer structure having a substrate of at least one ofsemiconductor or dielectric material which has traces formed by one ormore of the above-described methods, but which does not have activecircuit elements therein. An interposer structure or component inaccordance such embodiments can have conductive elements exposed at oneor more of the front and rear faces for interconnection with one or moreexternal components such as, for example, a microelectronic element,substrate or circuit panel.

The structures discussed above provide extraordinary three-dimensionalinterconnection capabilities. These capabilities can be used with chipsof any type. Merely by way of example, the following combinations ofchips can be included in structures as discussed above: (i) a processorand memory used with the processor; (ii) plural memory chips of the sametype; (iii) plural memory chips of diverse types, such as DRAM and SRAM;(iv) an image sensor and an image processor used to process the imagefrom the sensor; (v) an application-specific integrated circuit (“ASIC”)and memory. The structures discussed above can be utilized inconstruction of diverse electronic systems. For example, a system 900 inaccordance with a further embodiment of the invention includes astructure 906 as described above in conjunction with other electroniccomponents 908 and 910. In the example depicted, component 908 is asemiconductor chip whereas component 910 is a display screen, but anyother components can be used. Of course, although only two additionalcomponents are depicted in FIG. 23 for clarity of illustration, thesystem may include any number of such components. The structure 906 asdescribed above may be, for example, a composite chip or a structureincorporating plural chips. In a further variant, both may be provided,and any number of such structures may be used. Structure 906 andcomponents 908 and 910 are mounted in a common housing 901,schematically depicted in broken lines, and are electricallyinterconnected with one another as necessary to form the desiredcircuit. In the exemplary system shown, the system includes a circuitpanel 902 such as a flexible printed circuit board, and the circuitpanel includes numerous conductors 904, of which only one is depicted inFIG. 23, interconnecting the components with one another. However, thisis merely exemplary; any suitable structure for making electricalconnections can be used. The housing 901 is depicted as a portablehousing of the type usable, for example, in a cellular telephone orpersonal digital assistant, and screen 910 is exposed at the surface ofthe housing. Where structure 906 includes a light-sensitive element suchas an imaging chip, a lens 911 or other optical device also may beprovided for routing light to the structure. Again, the simplifiedsystem shown in FIG. 23 is merely exemplary; other systems, includingsystems commonly regarded as fixed structures, such as desktopcomputers, routers and the like can be made using the structuresdiscussed above.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

The invention claimed is:
 1. An assembly comprising: a first componentincluding a dielectric region having an exposed surface; a conductivepad at the surface permitting electrical interconnection of the firstcomponent with a second component, the conductive pad defined by aconductive element having at least a portion extending in at least oneof an oscillating or spiral path along the surface, the path beingformed so as to intersect a straight line along the surface more thanthree times, and at least two adjacent portions of the conductiveelement are separated by a portion of the surface not covered by theconductive element, the conductive element extending from the surface toa top surface at a height above the surface and having a length alongthe surface that is at least ten times greater than the height; and anelectrically conductive bonding material having a melting temperaturebelow 300° C. joined to the conductive pad and bridging the portion ofthe surface between the at least two adjacent portions of the conductiveelement, wherein the conductive element has side surfaces extending awayfrom the top surface and the conductive bonding material contacts thetop and side surfaces of the conductive element, wherein the path of theconductive element does at least one of: overlaps or crosses itself. 2.The assembly of claim 1, further comprising the second component havinga terminal joined to the conductive pad through the bonding material. 3.The assembly of claim 1, wherein the conductive element occupies lessthan seventy-five percent of an area of the surface of the dielectricregion within a circular boundary defined by outermost edges of the pad.4. The assembly of claim 1, wherein the first component further includesa substrate having a substrate surface, the dielectric region at leastpartly overlying the substrate surface.
 5. The assembly of claim 4,wherein the substrate surface is a top surface of the substrate, thesubstrate further having a bottom surface remote from the top surface,an opening extending between the top and bottom surfaces, and a secondconductive element disposed at the bottom surface, the pad beingelectrically connected to the second conductive element through theopening in the substrate and an opening in the dielectric region.
 6. Theassembly of claim 1, wherein the surface of the dielectric region isexposed at an exposed surface of the first component, the firstcomponent further having a bottom surface remote from the exposedsurface thereof, an opening extending between the exposed and bottomsurfaces thereof, and a second conductive element disposed at the bottomsurface, the pad being electrically connected to the second conductiveelement through the opening in the first component and an opening in thedielectric region.
 7. The assembly of claim 1, wherein the firstcomponent is a microelectronic element having a plurality of contacts ata surface thereof, further comprising a trace electrically connectingthe conductive pad with at least one of the plurality of contacts. 8.The assembly of claim 1, wherein the first component is a dielectricelement having a plurality of traces thereon, wherein the conductive padis electrically connected with at least one of the traces.
 9. Theassembly of claim 1, wherein the first component includes a firstsurface, the first component is a microelectronic element having aplurality of contacts at a second surface remote from the first surface,and the conductive pad is electrically connected with at least one ofthe plurality of contacts.
 10. The assembly of claim 1, wherein thebonding material is solder.
 11. The assembly of claim 1, wherein the padincludes a surface layer including at least one of nickel or gold, andthe bonding material contacts the surface layer.
 12. A system comprisingan assembly according to claim 1 and one or more other electroniccomponents electrically connected to the assembly.
 13. A system asclaimed in claim 12 further comprising a housing, the assembly and theother electronic components being mounted to the housing.
 14. Anassembly comprising: a first component including a dielectric regionhaving an exposed surface; a conductive pad at the surface permittingelectrical interconnection of the first component with a secondcomponent, the conductive pad defined by a conductive element having atleast a portion extending in at least one of an oscillating or spiralpath along the surface, the path being formed so as to intersect astraight line along the surface more than three times, and at least twoadjacent portions of the conductive element are separated by a portionof the surface not covered by the conductive element, the conductiveelement extending from the surface to a top surface at a height abovethe surface and having a length along the surface that is at least tentimes greater than the height; and an electrically conductive bondingmaterial having a melting temperature below 300° C. joined to theconductive pad and bridging the portion of the surface between the atleast two adjacent portions of the conductive element, wherein theconductive element has side surfaces extending away from the top surfaceand the conductive bonding material contacts the top and side surfacesof the conductive element, wherein the exposed surface of the firstcomponent is a rear face, and the first component has a front faceremote from the rear face and an opening extending between front andrear faces, and wherein the conductive element is exposed at the rearface and at least a portion of the conductive element extends along aninterior surface of the opening.
 15. The assembly of claim 14, whereinthe first component has at least one contact at the front face, whereinelectrical connection between the at least one contact and theconductive element is made through the opening.
 16. The assembly ofclaim 15, wherein the first component is a microelectronic elementhaving a plurality of active semiconductor devices adjacent the frontface.
 17. An assembly comprising: a first component including adielectric region having an exposed surface; a continuous grooveextending along the surface and having at least a portion extending in acurved path along the surface, the groove having a floor disposed belowthe surface; a conductive pad exposed at the surface permittingelectrical interconnection of the first component with a secondcomponent, the conductive pad defined by a conductive element havingcross-sectional dimensions at least partly defined by the groove,extending from the floor of the groove to a height above, the floor, andhaving at least a portion extending in at least one of an oscillating orspiral path along the surface, the path being formed so as to intersecta straight line along the surface more than three times, the conductiveelement having at least two adjacent portions separated by a portion ofthe surface of the dielectric region, and the conductive element havinga length along the surface that is at least ten times greater than theheight; and an electrically conductive bonding material having a meltingtemperature below 300° C. joined to the conductive pad and bridging theportion of the surface between the at least two adjacent portions of theconductive element.
 18. The assembly of claim 17, wherein the firstcomponent is a microelectronic element having a plurality of contacts ata surface thereof and a plurality of active semiconductor devicesadjacent the surface of the first component, the assembly furthercomprising a trace electrically connecting the conductive pad with atleast one of the plurality of contacts.
 19. The assembly of claim 17,wherein the first component is a dielectric element having a pluralityof traces thereon, wherein the conductive pad is electrically connectedwith at least one of the traces.
 20. The assembly of claim 17, whereinthe first component includes a first surface, the first component is amicroelectronic element having a plurality of contacts at a secondsurface remote from the first surface, and a plurality of activesemiconductor devices adjacent the second surface, and the conductivepad is electrically connected with at least one of the plurality ofcontacts.
 21. The assembly according to claim 17, 18, 19, or 20, furthercomprising the second component, the bonding material joining theconductive pad with a terminal of the second component.
 22. The assemblyof claim 17, wherein the bonding material is solder.
 23. The assembly ofclaim 17, wherein the first component includes a first surface, a secondsurface remote from the first surface, and an opening extending betweenthe first and second surfaces and at least a portion of the conductiveelement extends along an interior surface of the opening, at least aportion of the groove extends along the interior surface, the conductiveelement extending within the portion of the groove.
 24. The assembly ofclaim 23, wherein the first component includes a plurality of contactsat the second surface, at least one of the plurality of contacts beingelectrically connected to the conductive element through the opening.25. The assembly of claim 17, wherein the height of the conductiveelement is greater than a distance between the floor and the surface ofthe dielectric region.
 26. The assembly of claim 17, wherein the heightof the conductive element is equal to or less than a distance betweenthe floor and the surface of the dielectric region.
 27. The assembly ofclaim 17, wherein outermost edges of the pad define a circular orsquare-shaped boundary with respect to the surface.
 28. The assembly ofclaim 27, wherein the path of the conductive element does not overlap orcross itself.
 29. The assembly of claim 27, wherein the path of theconductive element does at least one of overlap or cross itself.
 30. Theassembly of claim 27, wherein the conductive element occupies less thanseventy-five percent of the surface area of the surface within theboundary.
 31. The assembly of claim 17, wherein the height of theconductive element is greater than a distance between the floor and thesurface such that the conductive element has top surface exposed at thesurface of the dielectric region and side surfaces extending away fromthe top surface, the bonding material contacting the top and sidesurfaces of the conductive element.
 32. The assembly of claim 17,wherein the pad includes a surface layer including at least one ofnickel or gold.
 33. The assembly of claim 17, wherein the surface of thedielectric region is exposed at an exposed surface of the firstcomponent, the first component further having a bottom surface opposedfrom the exposed surface thereof, an opening extending between theexposed and bottom surfaces thereof, and a second conductive elementoverlying the bottom surface, the pad being electrically connected tothe second conductive element through the opening in the first componentand an opening in the dielectric region.
 34. The assembly of claim 17,wherein the dielectric region includes a solder mask.
 35. The assemblyof claim 17, wherein the dielectric region is a polymeric material. 36.The assembly of claim 17, wherein the dielectric region is an inorganicmaterial.
 37. The assembly of claim 17, wherein the dielectric regioncomprises two or more stacked layers of dielectric materials, at leasttwo adjacent layers thereof including different materials.
 38. A systemcomprising an assembly according to claim 17 and one or more otherelectronic components electrically connected to the assembly.
 39. Asystem as claimed in claim 38 further comprising a housing, the assemblyand the other electronic components being mounted to the housing.
 40. Amethod comprising: (a) providing a lead frame having a conductive pad,the conductive pad defined by a conductive element extending along asurface of the lead frame and having at least a portion extending in acurved path along the surface; (b) at least partially embedding the leadframe in a dielectric material to form a first component, wherein theconductive pad is exposed at a surface of the dielectric material forpermitting electrical interconnection of the first component with asecond component, the conductive element of the conductive pad having atleast a portion extending in at least one of an oscillating or spiralpath along the surface of the dielectric region, the path being formedso as to intersect a straight line along the surface more than threetimes, the conductive element having at least two adjacent portionsthereof separated by a portion of the surface of the dielectric regionbetween the at least two portions of the conductive element, theconductive element having a length along the surface of the dielectricregion that is at least ten times greater than a height of theconductive element above the surface of the dielectric region; and (c)applying an electrically conductive bonding material having a meltingtemperature below 300° C. to the conductive pad, the electricallyconductive bonding material bridging the portion of the surface betweenthe at least two adjacent portions of the conductive element.
 41. Themethod of claim 40, wherein step (c) includes assembling the firstcomponent with the second component with the bonding material joiningthe conductive pad to a conductive pad of the second component.
 42. Amethod comprising: (a) forming a continuous groove extending along asurface of a dielectric region of a first component by removing aportion of the dielectric region, the groove having at least a portionextending in a curved path, the groove having a floor disposed below thesurface; (b) forming a conductive pad exposed at the surface permittingelectrical interconnection of the first component with a secondcomponent, the conductive pad defined by a conductive element havingcross-sectional dimensions and a path at least partly defined by thepath of the groove and extending from the floor of the groove to aheight above the floor, the conductive element having at least a portionextending in at least one of an oscillating or spiral path along thesurface, the path being formed so as to intersect a straight line alongthe surface more than three times, the conductive element having atleast two adjacent portions separated by a portion of the surface, theconductive element having a length along the surface that is at leastten times greater than the height, the conductive element at leastpartially embedded in the groove; and (c) assembling the first componentwith the second component with an electrically conductive bondingmaterial having a melting temperature below 300° C. joining theconductive pad to a conductive pad of the second component, theelectrically conductive bonding material bridging the portion of thesurface of the dielectric region between the at least two adjacentportions of the conductive element.
 43. A method comprising: (a) platinga conductive pad onto a planar surface of a mandrel, the conductive paddefined by a conductive element extending along the surface and havingat least a portion extending in a curved path along the surface; (b) atleast partially embedding the conductive pad into a dielectric materialto form a first component; (c) removing the mandrel to form the firstcomponent having a dielectric region and the conductive pad exposed at asurface of the dielectric region for permitting electricalinterconnection of the first component with a second component, theconductive element of the conductive pad having at least a portionextending in at least one of an oscillating or spiral path along thesurface of the dielectric region, the path being formed so as tointersect a straight line along the surface of the dielectric regionmore than three times, the conductive element having at least twoadjacent portions thereof separated by a portion of the surface of thedielectric region, the conductive element having a length along thesurface of the dielectric region that is at least ten times greater thana height of the conductive element above the surface of the dielectricregion; and (d) assembling the first component with the second componentwith an electrically conductive bonding material having a meltingtemperature below 300° C. joining the conductive pad to a conductive padof the second component, the electrically conductive bonding materialbridging the portion of the surface of the dielectric region between theat least two adjacent portions of the conductive element.
 44. A methodcomprising: (a) providing a lead frame having a conductive pad, theconductive pad defined by a conductive element extending along a surfaceof the lead frame and having at least a portion extending in a curvedpath along the surface; (b) at least partially embedding the lead framein a dielectric material to form a first component, wherein theconductive pad is exposed at a surface of the dielectric material forpermitting electrical interconnection of the first component with asecond component, the conductive element of the conductive pad having atleast a portion extending in at least one of an oscillating or spiralpath along the surface of the dielectric region, the path being formedso as to intersect a straight line along the surface more than threetimes, the conductive element having at least two adjacent portionsthereof separated by a portion of the surface of the dielectric regionbetween the at least two portions of the conductive element, theconductive element having a length along the surface of the dielectricregion that is at least ten times greater than a height of theconductive element above the surface of the dielectric region; and (c)assembling the first component with the second component with anelectrically conductive bonding material having a melting temperaturebelow 300° C. joining the conductive pad to a conductive pad of thesecond component, the electrically conductive bonding material bridgingthe portion of the surface of the dielectric region between the at leasttwo adjacent portions of the conductive element.
 45. A methodcomprising: (a) forming a continuous groove extending along a surface ofa dielectric region of a first component by removing a portion of thedielectric region, the groove having at least a portion extending in acurved path, the groove having a floor disposed below the surface; (b)forming a conductive pad exposed at the surface permitting electricalinterconnection of the first component with a second component, theconductive pad defined by a conductive element having cross-sectionaldimensions and a path at least partly defined by the path of the grooveand extending from the floor of the groove to a height above the floor,the conductive element having at least a portion extending in at leastone of an oscillating or spiral path along the surface, the path beingformed so as to intersect a straight line along the surface more thanthree times, the conductive element having at least two adjacentportions separated by a portion of the surface, the conductive elementhaving a length along the surface that is at least ten times greaterthan the height, the conductive element at least partially embedded inthe groove; and (c) applying an electrically conductive bonding materialhaving a melting temperature below 300° C. to the conductive pad, theelectrically conductive bonding material bridging the portion of thesurface between the at least two adjacent portions of the conductiveelement.
 46. The method of claim 45 or claim 42, wherein the height ofthe conductive element is greater than a distance between the floor andthe surface.
 47. The method of claim 46, wherein the conductive elementincludes an exposed top surface parallel to the surface of thedielectric region and exposed vertical surfaces extending between thetop surface thereof and the surface of the dielectric region, thebonding material being in contact with the top and vertical surfaces ofthe conductive element.
 48. The method of claim 45 or claim 42, whereinthe height of the conductive element is equal to or less than a distancebetween the floor and the surface.
 49. The method of claim 45 or claim42, wherein a distance between the floor and the surface is greater thana width of the conductive element.
 50. The method of claim 45 or claim42, wherein step (b) includes forming the conductive element such thatit does not overlap or cross itself.
 51. The method of claim 45 or claim42, wherein step (b) includes forming the conductive element such thatit does at least one of: overlaps or crosses itself.
 52. The method ofclaim 45 or claim 42, wherein step (b) includes forming a catalyst layeroverlying at least the floor of the groove, and then selectivelydepositing a metal onto an area where the catalyst layer is present toform the conductive element.
 53. The method of claim 45 or claim 42,wherein the bonding material extends at least between outermost edges ofthe pad of the first component.
 54. The method of claim 45 or claim 42,wherein step (b) includes plating a surface layer including at least oneof nickel or gold exposed at a surface of the pad of the firstcomponent.
 55. The method of claim 45 or claim 42, wherein the firstcomponent includes a second region, the dielectric region overlying thesecond region when step (a) and step (b) are performed.
 56. The methodof claim 55, wherein the first component further includes a substratehaving a top surface, a bottom surface opposed from the top surface, anopening extending between the top and bottom surfaces, and a conductiveelement overlying the bottom surface, the pad of the first componentbeing electrically connected to the conductive element of the substratethrough the opening in the substrate and an adjacent opening in thedielectric region.
 57. The method of claim 45 or claim 42, wherein step(a) is performed by processing including at least one of: directing alaser toward at least the surface to ablate the portion of thedielectric region, mechanical milling, or sandblasting.
 58. The methodof claim 45 or claim 42, wherein step (a) includes positioning a metalstencil to overlie the dielectric region, the metal stencil having atleast one opening, and removing the portion of the dielectric regionexposed through the at least one opening by sandblasting.
 59. The methodof claim 45 or claim 42, wherein step (a) includes removing a portion ofthe dielectric region by mechanical milling.
 60. The method of claim 45or claim 42, wherein step (b) includes depositing a conductive materialoverlying the surface of the dielectric region and at least a portion ofthe groove, and removing the conductive material overlying at least aportion of the surface to expose the surface of the dielectric region.61. The method of claim 45, wherein step (c) includes applying thebonding material to the conductive pad, the bonding material bridgingthe exposed portion of the surface between the at least two adjacentportions of the conductive element.
 62. The method of claim 45, whereinstep (c) includes assembling the first component with the secondcomponent with the bonding material joining the conductive pad to aconductive pad of the second component, the bonding material bridgingthe portion of the surface of the dielectric region between the at leasttwo adjacent portions of the conductive element.
 63. A methodcomprising: (a) plating a conductive pad onto a planar surface of amandrel, the conductive pad defined by a conductive element extendingalong the surface and having at least a portion extending in a curvedpath along the surface; (b) at least partially embedding the conductivepad into a dielectric material to form a first component; (c) removingthe mandrel to form the first component having a dielectric region andthe conductive pad exposed at a surface of the dielectric region forpermitting electrical interconnection of the first component with asecond component, the conductive element of the conductive pad having atleast a portion extending in at least one of an oscillating or spiralpath along the surface of the dielectric region, the path being formedso as to intersect a straight line along the surface of the dielectricregion more than three times, the conductive element having at least twoadjacent portions thereof separated by a portion of the surface of thedielectric region, the conductive element having a length along thesurface of the dielectric region that is at least ten times greater thana height of the conductive element above the surface of the dielectricregion; and (d) applying an electrically conductive bonding materialhaving a melting temperature below 300° C. to the conductive pad, theconductive bonding material bridging the portion of the surface betweenthe at least two adjacent portions of the conductive element.
 64. Themethod of claim 63 or claim 43, wherein the mandrel includes a metalsheet, and step (c) includes etching the metal sheet to expose the padof the first component.
 65. The method of claim 63 or claim 43, whereinstep (b) includes embedding the conductive pad of the first componentinto an at least partially cured dielectric region which includes thedielectric material.
 66. The method of claim 63 or claim 43, whereinstep (b) includes depositing the dielectric material to contact at leasta portion of the conductive pad of the first component.
 67. The methodof claim 63, wherein step (d) includes assembling the first componentwith the second component, with the bonding material joining theconductive pad to a conductive pad of the second component.